In the area of wire communications, there are electrical and optical communication links between equipment. An electrical link commonly comprises an electrical transmitter and an electrical receiver that are connected by metal wire. The electrical transmitter converts information to an electrical signal and then transmits it over the metal wire which acts as a transmission medium. The electrical receiver converts the received electrical signal back to useful information. An optical link generally comprises an optical transmitter and an optical receiver component that are connected by a fiber optic cable. The optical transmitter typically comprises a light source, such as, for example, a light-emitting diode (LED), which converts an electrical data signal into a modulated light signal. This light signal is transmitted through fiber optic cable and is received by the optical receiver, which generally comprises a light detector, such as, for example, a photosensor, photodiode, etc. The optical receiver converts the light signal back into an electrical data signal.
The housing of an optical transmitter or receiver includes appropriate electrical pins which provide an electrical input/output (I/O) data interface with the communications equipment. The front face of the housing (which comprises a plastic or similar material) includes an alignment port for receiving a fiber optic connector to which a fiber optic cable is terminated. The optical transmitter and receiver are connected by an optical fiber.
To secure the fiber optic connector within the alignment port, the housing may also include features for retaining the connector in the alignment port. A typical industrial connector such as Versatile Link includes a horizontal C-shaped feature defined by opposing elements that protrude from the front face at the alignment port.
The use of fiber optics provides a number of advantages over metal wires. Fiber optic cable allows the transport of data signals over longer distances. Fiber cables are lighter than metal wires because they are made of clear glass, polymer, or similar materials. The fiber optic cable is non-conductive and, therefore, protects against electrical shorts and lightning strikes. Optical signals are not degraded by electromagnetic interference (EMI) and, therefore, may provide better signal integrity than metal wires. Optical fiber also provides better data security protection because it is much more difficult to tap signals along a fiber.
In fiber optic applications, the polymer optical fiber (POF) cable is more cost effective than glass optical fiber cable. It also provides easy field termination and is less sensitive to dust contamination due to large fiber core diameter.